This invention relates to methods and apparatus for peeling adhesive labels from a release coated web tape supply, while holding the peeled label, and applying the label precisely onto an item. It relates to adhesive components other than labels also.
Adhesive labels are generally supplied on a large tape roll of release coated web. The labels may be preprinted or may be printed in the label dispensing apparatus. Automatic peel and apply apparatus of the prior art generally holds the roll of labels and pulls the web, label side up, over a plate with a sharp edge and then pulls the web beneath the plate so that the label extends tangentially from the edge free of the web as the web changes direction. The label is grasped by its non-adhesive surface with a vacuum holder as it is released from the web. Problems arise in the methods of holding the label as it is released to ensure precision of final placement onto the item being labelled. The labels may not be uniformly spaced on the tape. If the label is not stiff enough, the label may wrinkle or bend as it is being released and grasped. To overcome such problems, the label designer may be forced to use a stiffer material than is otherwise desired. Since the holder must be at the edge of the peel plate as the label is peeled, it must be translated clear of the plate before it can be lowered onto an item in a complex motion that may be difficult to control precisely. U.S. Pat. No. 4,581,094 issued Apr. 8, 1986 to Sato translates the vacuum holder past the plate edge in synchronism with the tape travel. U.S. Pat. No. 4,687,535 issued Aug. 18, 1987 to Voltmer uses a vacuum drum that rotates past the peel plate edge. These and the other prior art label dispensers, as far as we know, all use a peel plate that does not move. They have various complex mechanisms that are expensive to manufacture and maintain and that often lack precision of placement.